Delirium May Accelerate Decline in Alzheimer's Disease

Cognitive function declines faster after an episode of delirium

06 may 2009-- Patients with Alzheimer's disease have a greater acceleration in cognitive decline after an episode of delirium, according to a study in the May 5 issue of Neurology.

Tamara G. Fong, M.D., from the Beth Israel Deaconess Medical Center in Boston, and colleagues analyzed cognitive performance in elderly patients with Alzheimer's disease, where 72 developed delirium and 336 did not develop delirium.

The researchers found that the rate of cognitive decline, as assessed by changes in the Information-Memory-Concentration (IMC) subtest of the Blessed Dementia Rating Scale, significantly accelerated after an episode of delirium. The average decline on the IMC was 2.5 points per year but further declined to an average of 4.9 points per year after an episode of delirium. Patients who developed delirium had a threefold higher rate of change in the IMC score, according to the study.

"Delirium can accelerate the trajectory of cognitive decline in patients with [Alzheimer's] disease (AD)," Fong and colleagues conclude. "Ultimately, the information derived from this study provides the foundation for future randomized intervention studies to determine whether prevention of delirium might ameliorate and/or delay cognitive decline in patients with AD."

Abstract
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